This invention relates to radiation sensitive louvered systems constructed to shield a surface from the effects of rapid onset of high intensity radiation. Louvers of this type find application in space vehicle systems to shield surfaces such as solar cell panels, thermal radiators, and the like, from high intensity radiation.
Previously known devices in the field of the present invention finding substantial use employed thermally sensitive bimetallic elements to serve as the closure means for the louvers. In this application, bimetallic elements may be inadequate principally because they respond in a manner and to a degree substantially proportional to the change in temperature. Substantially immediate and total response of these devices to the onset of radiation is therefore precluded.
The present invention eliminates or substantially reduces in critical importance the aforementioned deficiencies in previously known devices by providing a novel radiation protection louver having a thermally sensitive closure means comprising a hinge of substantially equiatomic martensitic structure alloy, such as titanium nickel. The louver of this invention activates substantially immediately and totally when the transition temperature of the alloy member comprising the hinge is reached, and thereby responds in virtually an on-off mode. By suitable selection of alloy composition, the activation temperature of the louver (transition temperature for the alloy hinge member) may be specifically predetermined over a wide temperature range from about -50.degree. C. to about 166.degree. C. The louver of this invention may be reactivated repeatedly, may be applied to shield large surface areas with one or a plurality of louver blades, and may be made to operate independently of other control systems.
It is, therefore, an object of this invention to provide an improved radiation sensitive protective louver system.
It is a further object of this invention to provide a radiation protection louver which responds rapidly upon exposure to high intensity radiation.
These and other objects of the present invention will become apparent as the detailed description of a representative embodiment thereof proceeds.